vaadin.whitelisted-packages breaks LitRenderer

[Frettman]

Any non-trivial Spring Boot application seems to require vaadin.whitelisted-packages to be set, otherwise the application start takes much too long, at least in dev mode.
But when I set the whitelist to the root package of my application, there seem to be some built-in parts of Vaadin that break. More specifically I experience this for the com.vaadin.flow.data.renderer.LitRenderer. I can find lit-renderer.ts in target/flow-frontend but it does not seem to get loaded: window.Vaadin.setLitRenderer is not a function.
When I remove the whitelist and restart the application it starts working again.
Adding com.vaadin to the whitelist also seems to do the trick. But I was under the impression this shouldn't be necessary? At least there doesn't seem to be any mention of this anywhere.

As I have mentioned in #620, I would really appreciate a mechanism that allows add-ons to automatically contribute packages that they need to have scanned. This would make having to micromanage vaadin.whitelisted-packages obsolete in the first place.

[caalador]

The default scanned packages for a whitelist always include the package of Component (com.vaadin.flow.component), Theme (com.vaadin.flow.theme) and com.vaadin.shrinkwrap as those have been the only places with annotations to take into account as renderers have not used any annotations.

Seems this changed in 22.0.0.alpha2 when LitRenderer was added.